public IfStatement Parse()
{
PeekToken();
if (!Test(Token.Type.If, IfState.PreLeftPar) ||
!Test(Token.Type.LeftPar, IfState.PreExpr))
{
return(null);
}
PeekToken(IfState.PostExpr);
var cond = lastToken.GetData <IBaseExpression>();
Expect(Token.Type.RightPar, IfState.PreBlock);
PeekToken(IfState.PostBlock);
IBaseStatement
ifBlock = lastToken.GetData <IBaseStatement>(),
elseBlock = null;
if (Test(Token.Type.Else, IfState.PostElse))
{
CommitPeek();
elseBlock = lastToken.GetData <IBaseStatement>();
}
else
{
SetState(IfState.End);
}
return(new IfStatement(cond, ifBlock, elseBlock));
}
public DelegateT Parse()
{
var method = new DynamicMethod(
"Evaluate",
typeof(long),
new Type[] { typeof(long), typeof(long), typeof(long) }
);
var generator = method.GetILGenerator();
PeekToken();
if (TestNoShift(Token.Type.VarDefStatement))
{
VarDefStatement defStt = token.GetData <VarDefStatement>();
defStt.Emit(generator);
int i = 0;
defStt.names.ForEach(name => vars[name] = new Variable(name, i++, true));
PeekToken(ProgramState.AfterDef);
}
foreach (var(name, obj) in globalVars)
{
if (!vars.ContainsKey(name))
{
vars[name] = obj;
}
}
IBaseStatement stt = null;
bool returns = false;
while (HasToken())
{
stt = token.GetData <IBaseStatement>();
returns |= stt.CheckReturn();
stt.Emit(generator);
CommitPeek();
if (lexer.Source.CommitAndCheckIsEnd())
{
break;
}
RePeekToken(ProgramState.AfterDef);
}
if (!returns)
{
throw new CompileException(
"end of function is reachable without any return statement"
);
}
if (!(stt is ReturnStatement))
{
new ReturnStatement(new Const(0)).Emit(generator); // load dummy to not get error
}
return((DelegateT)method.CreateDelegate(typeof(DelegateT)));
}
public IfStatement(
IBaseExpression condition,
IBaseStatement ifBranch,
IBaseStatement elseBranch = null
)
{
IBaseExpression.CheckTypes(
"if condition", "",
typeof(bool), condition.GetResultType()
);
this.condition = condition;
precalc = (bool?)condition.Evaluate();
this.ifBranch = ifBranch;
this.elseBranch = elseBranch;
}
